<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../react18/react.development.js"></script>
  <script src="../react18/react-dom.development.js"></script>
  <script src="../react18/babel.min.js"></script>
</head>

<body>
  <div id="app"></div>
  <script type="text/babel">

    /* class App extends React.Component{
      state = {
        count:0,
        isHot:true
      }

      render(){
        console.log("----render----");
        const {count,isHot} = this.state;
        return (
          <div>
            <button onClick={this.handle} >+</button>
            <p>{count}</p>

            <button onClick={this.changeWeaHandle}>切换天气</button>
            <p>{isHot?"热啊":"冷啊"}</p>
          </div>
        )
      }

      //事件函数
      handle = () => {
        let {count} = this.state;
        // this.setState({count:++count})
        this.setState({count:count + 1})
      }

      changeWeaHandle = () => {
        const {isHot} = this.state;
        this.setState({isHot:!isHot})
      }
    }

    const root = ReactDOM.createRoot(document.getElementById('app'));
    root.render(<App/>) */




    class App extends React.Component{
      state = {
        count: 1,
        isHot: true,
      }

      render(){
        const {count,isHot} = this.state;
        return(
          <div>
            <button onKeyDown = {this.handleAdd} >+</button>
            <br/>
            <button onKeyDown = {this.handleLess}>-</button>
            <h1>{count}</h1>

            <button onClick = {this.changeWeaHandle}>切换</button>
            <p>今天真<span style = {{color:"red",fontSize: "40px"}}>{isHot?"热" : "冷"}</span>啊</p>
          </div>
        )
      }

      handleAdd = ()=>{
        let {count} = this.state;
        // this.setState({count: ++count})
        this.setState({count: count + 1})
      }

      handleLess = ()=>{
        let {count} = this.state;
        // this.setState({count: --count})
        this.setState({count: count - 1})
      }

      changeWeaHandle = ()=>{
        let {isHot} = this.state;
        this.setState({isHot:!isHot})
      }

    }

    const root = ReactDOM.createRoot(document.getElementById('app'))
    root.render(<App/>)





  </script>
</body>

</html>